NAME

SYNOPSIS

saned[-a[username]|-d[n]|-s[n]]

DESCRIPTION

saned is the SANE (Scanner Access Now Easy) daemon that allows remote
clients to access image acquisition devices available on the local
host.

OPTIONS

The -a flag requests that saned run in standalone daemon mode. In this
mode, saned will detach from the console and run in the background,
listening for incoming client connections; inetd is not required for
saned operations in this mode. If the optional username is given after
-a , saned will drop root privileges and run as this user (and group).
The -d and -s flags request that saned run in debug mode (as opposed to
inetd(8) mode). In this mode, saned explicitly waits for a connection
request. When compiled with debugging enabled, these flags may be
followed by a number to request debug info. The larger the number, the
more verbose the debug output. E.g., -d128 will request printing of
all debug info. Debug level 0 means no debug output at all. The default
value is 2. If flag -d is used, the debug messages will be printed to
stderr while -s requests using syslog.
If saned is run from inetd or xinetd, no option can be given.

CONFIGURATION

First and foremost: saned is not intended to be exposed to the internet
or other non-trusted networks. Make sure that access is limited by
tcpwrappers and/or a firewall setup. Don’t depend only on saned’s own
authentification. Don’t run saned as root if it’s not necessary. And do
not install saned as setuid root.
The contents of the saned.conf file is a list of host names, IP
addresses or IP subnets (CIDR notation) that are permitted to use local
SANE devices. IPv6 addresses must be enclosed in brackets, and should
always be specified in their compressed form. Connections from
localhost are always permitted. Empty lines and lines starting with a
hash mark (#) are ignored. A line containing the single character
‘‘+’’ is interpreted to match any hostname. This allows any remote
machine to use your scanner and may present a security risk, so this
shouldn’t be used unless you know what you’re doing. A sample
configuration file is shown below:
scan-client.somedomain.firm
# this is a comment
192.168.0.1
192.168.2.12/29
[::1]
[2001:7a8:185e::42:12]/64
The case of the host names does not matter, so AHost.COM is considered
identical to ahost.com.

INETDCONFIGURATION

For saned to work properly in its default mode of operation, it is also
necessary to add a configuration line to /etc/inetd.conf. Note that
your inetd must support IPv6 if you want to connect to saned over IPv6
; xinetd and openbsd-inetd are known to support IPv6, check the
documentation for your inetd daemon.
The configuration line normally looks like this:
sane-port stream tcp nowait saned.saned /usr/sbin/saned saned
However, if your system uses tcpd(8) for additional security screening,
you may want to disable saned access control by putting ‘‘+’’ in
saned.conf and use a line of the following form in /etc/inetd.conf
instead:
sane-port stream tcp nowait saned.saned /usr/sbin/tcpd
/usr/sbin/saned
Note that both examples assume that there is a saned group and a saned
user. If you follow this example, please make sure that the access
permissions on the special device are set such that saned can access
the scanner (the program generally needs read and write access to
scanner devices).
If xinetd is installed on your system instead of inetd the following
example for xinetd.conf may be helpful:
# default: off
# description: The sane server accepts requests
# for network access to a local scanner via the
# network.
service sane-port
{
port = 6566
socket_type = stream
wait = no
user = saned
group = saned
server = /usr/sbin/saned
}
Finally, it is also necessary to add a line of the following form to
/etc/services:
sane-port 6566/tcp # SANE network scanner daemon
The official IANA short name for port 6566 is "sane-port". The older
name "sane" is now deprecated.

RESTRICTIONS

In addition to the control connection (port 6566 ) saned also uses a
data connection. The port of this socket is selected by the operating
system and can’t be specified by the user currently. This may be a
problem if the connection must go through a firewall (packet filter).
If you must use a packet filter, make sure that all ports > 1024 are
open on the server for connections from the client.

FILES

/etc/hosts.equiv
The hosts listed in this file are permitted to access all local
SANE devices. Caveat: this file imposes serious security risks
and its use is not recommended.
/etc/sane.d/saned.conf
Contains a list of hosts permitted to access local SANE devices
(see also description of SANE_CONFIG_DIR below).
/etc/sane.d/saned.users
If this file contains lines of the form
user:password:backend
access to the listed backends is restricted. A backend may be
listed multiple times for different user/password combinations.
The server uses MD5 hashing if supported by the client.

ENVIRONMENT

SANE_CONFIG_DIR
This environment variable specifies the list of directories that
may contain the configuration file. Under UNIX, the directories
are separated by a colon (‘:’), under OS/2, they are separated
by a semi-colon (‘;’). If this variable is not set, the
configuration file is searched in two default directories:
first, the current working directory (".") and then in
/etc/sane.d. If the value of the environment variable ends with
the directory separator character, then the default directories
are searched after the explicitly specified directories. For
example, setting SANE_CONFIG_DIR to "/tmp/config:" would result
in directories "tmp/config", ".", and "/etc/sane.d" being
searched (in this order).